Dynamoelectric devices include among other things electric generators, alternators, actuators, and motors. An electric generator is a device that converts mechanical energy to electrical energy. In contrast an electrical motor converts electrical energy to mechanical energy. A typical electrical generator includes a stationary structure referred to as the stator, and a rotating part referred to as the rotor. Typically the rotor includes permanent magnets or electro magnets that are designed to rotate relative to a coil that is wound around the stator. The motion of the magnets relative to the coil produces electrical current in the coil. The current producing coil is also called an armature. Optionally, the armature may be placed on the rotor with the magnets on the stator instead of the opposite situation described above.
The current flowing in the coil produces heat, which also increases the resistance of the coil and reduces the effectiveness of the dynamoelectric device. There is thus an interest in lowering the heat buildup in the coil during operation of generators and other dynamoelectric devices.